BEFstar.tec and BEFstarObf.tec are from Tom Eklo:f <Tom.Eklof@laurea.fi>, 
who writes:

Here is, in all its gory glory, my implementation of BF in TECO, named, 
aptly enough, Brain Editor and Fucker or BEF* for short.

Included are two files. BEFstar.tec is the commented, nonobfuscated 
version of the source. BEFstarObf.tec is TECO at its best (ie. looks 
completely hideous).



To actually use the interpreter, you need an implementation of TECO, 
preferably TECOC from http://almy.us/files/tecoclinux0398.tar.gz which 
is what I tested my program on. Any TECO-11 v40 compliant implementation 
should (NOT TESTED) work.

Now, start TECO up, and when you get its prompt (a *), type
eiBEFstar.tec$$
($$ means <ESC><ESC>, ie. press the ESC key 2 times)

Now BEF* will start interpreting the BF program at the start of the 
buffer. I've conveniently included a couple of programs in the .tec 
file, namely 99 Bottles, 'cat' and Fibonacci (which it runs by default). 
To run a program other than Fibonacci, put a ! before and a ! after it, 
and then uncomment (ie. remove the preceding and trailing !) another 
one.

Now, be warned, there are some serious bugs in the implementation: it 
does no bounds checking, so if you move off the right end of your memory 
(30000 bytes), you'll actually end up staring at the BF program, which 
is sitting in the buffer right there next to the memory. Also, ',' can 
only accept keyboard input and an ENTER keypress incorrectly issues 
<CR><LF> instead of just a <LF>.

Oh, and some programs just refuse to run. But that's life.
